Rainfall chiller

ABSTRACT

A counterflow chiller for cooling products on a conveyor employs a plurality of recirculating cooling modules in fluid communication with each other. Each recirculating cooling module sprays coolant over a portion of the conveyor to adjust the temperature of a product on the conveyor. An axial pump pumps coolant from a reservoir in a first recirculating coolant module to a sprayer, which sprays coolant over the product. Overflow coolant spills from one recirculating cooling module to another recirculating cooling module operating at a higher equilibrium temperature.

RELATED APPLICATIONS

The present invention claims priority to U.S. Provisional Patent Application No. 61/875,177, entitled Rainfall Chiller, filed Sep. 9, 2013, the contents of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

The invention relates generally to cooling systems for items on a conveyor. More particularly, the invention relates to a counterflow rainfall chilling system for cooling items on a conveyor or other moving substrate or transporter.

Chillers have been used to reduce the temperature of products. Examples of products that may require chilling include hot cooked foods, such as vegetables, shrimp and other animals, and other known products. Rainfall chillers operate by spraying coolant, such as water or another fluid, over items conveyed beneath the spray to reduce the temperature of the items through heat transfer with the incoming coolant. The temperature and/or volume of the incoming coolant may be controlled to control the cooling process.

SUMMARY OF THE INVENTION

A counterflow chilling system employs a series of recirculating cooling modules for cooling product passing through the series on a conveyor. A recirculating cooling module comprises a reservoir for collecting coolant below the conveyor, a pump for pumping coolant from the reservoir, a sprayer for spraying pumped coolant over the product and a spillover opening for passing overflow coolant from the reservoir into an adjacent recirculating cooling module or a system outlet. The chilling system forms a series of recirculating zones operating at increasing equilibrium temperatures.

According to one aspect, a chilling system for chilling products comprises a conveyor for conveying a product and a plurality of recirculation modules. Each recirculation module comprises a reservoir below the conveyor, a pump for pumping coolant from the reservoir, a pan for spraying pumped coolant over the product on the conveyor, and an outlet passageway in the reservoir for passing coolant into an adjacent reservoir or an outlet of the chilling system.

According to another aspect of the invention, recirculating module for a chiller comprises a reservoir having an inlet opening and a spillover opening, an inlet for a conveyor above the spillover opening, an outlet for the conveyor above the spillover opening, a pump having a pump inlet in communication with the reservoir and a pump outlet. The module also includes a sprayer in communication with the pump outlet for spraying pumped coolant over items on the conveyor.

According to another aspect, a method of changing the temperature of a product on a conveyor comprises the steps of conveying a product through a chiller, spraying coolant over the product in a first zone using a first sprayer, collecting sprayed coolant in the first zone, pumping sprayed coolant in the first zone back to the first sprayer, passing overflow coolant from the first zone into a second zone and spraying coolant over the product in the second zone using a second sprayer.

BRIEF DESCRIPTION OF THE DRAWINGS

These features and aspects of the invention, as well as its advantages, are better understood by referring to the following description, appended claims, and accompanying drawings, in which:

FIG. 1 is a front view of a chilling system according to an illustrative embodiment of the invention;

FIG. 2 is a front view of a single module of the chilling system of FIG. 1;

FIG. 3 is a cross-sectional view of the module of FIG. 2 through lines A-A;

FIG. 4 is a front view of the module of FIG. 2 in a cleaning mode; and

FIG. 5 is a cross-sectional view of the module of FIG. 4 in the cleaning mode through lines B-B.

DETAILED DESCRIPTION OF THE INVENTION

A counterflow rainfall chilling system employs recirculating modules that spill coolant into a subsequent module. The invention will be described below relative to an illustrative embodiment. Those skilled in the art will recognize that the invention is not limited to the illustrative embodiment.

FIG. 1 is a front view of an embodiment of a chilling system 10. The chilling system is used to reduce or otherwise modify the temperature of items conveyed on a conveyor, illustrated as a conveyor belt 20, or other moving substrate. The illustrative conveyor comprises a conveyor belt 20 trained around sprockets 21, though any suitable means for conveying products through the chilling system may be used.

The chilling system comprises a series of modules 100 a-100 d arranged side-by-side and in fluid communication with each other. Each module recirculates a coolant, such as water, over the product. The illustrative chilling system consists of four modules in series, but the invention may comprise any suitable number of modules.

The chiller 10 includes a coolant inlet 13 for inputting a coolant, such as cold water, into the system. Each module corresponds to and creates a temperature zone in a selected section of the conveyor to modify the temperature of the product. The temperature zone of the first module 100 a is the coldest and the temperature zone of the last module 100 d is the warmest. The spent coolant exits the chiller at an outlet 15. The spent coolant may be recycled, recirculated or discharged.

In the illustrative embodiment, hot product enters the chiller at the first end 11 and cool product exits the chiller at the second end 12. The change in temperature in the product occurs in stages. The chilling system transports hot products upstream in a flow path towards incoming chilled coolant, so that hotter products are partly cooled by the warmer part of the coolant heated by products being cooled, and are transported towards the cooler coolant source 13 as they become cooler. The conveyor belt 20 conveys product at a first, relatively high temperature into a first end 11 of the chiller, and through each of the modules. Each module modifies, preferably reduces, the temperature of the product such that product is conveyed out a second end 12 of the chiller at a second, relatively lower temperature.

Each module 100 recirculates coolant and sprays the coolant over the product to effect cooling. From the coolant inlet 13, coolant passes to an inlet pan 101 in communication with a first module 100 a. The inlet pan 101 feeds the coolant to a reservoir 110 of the first module, shown in FIGS. 2 and 3. The reservoir 110 is below the conveyor 20. A pump, illustrated as an axial pump 120, pulls coolant from the reservoir 110 and passes the coolant to a flow distribution pan 140, which feeds the coolant to spray pans 150 above the conveyor belt 20. The spray pans 150 rain the coolant onto the product to cool, or otherwise change the temperature of, the product. The conveyor 20 is foraminous or otherwise configured to allow the passage of coolant therethrough, so that the spent coolant passes back into the reservoir 110 for recirculation.

In the illustrative embodiment, each module includes four adjacent spray pans 150, various suitable embodiments of which are known in the art. The spray pan 150 is removably coupled to the frame for each module 100. The spray pan 150 includes an array of openings for creating a rainfall-like spray over the product. In the illustrative embodiment, each spray pan 150 spans the width of the conveyor belt 20. The frame of each module includes means for locking the spray pan into place. As shown in FIGS. 4 and 5, each pan 150 can lock in an up position for cleaning. A latch 155 may be used to lock the pan 150 in an operating position during operation.

The illustrative axial pump 120 includes an inlet 121, an outlet 122, housing 130, motor 124, a shaft 125 and propeller 126 driven by the motor 124. The housing 130 includes a removable shroud 131, as shown in FIG. 3. The shroud may be removed to access the propellers for cleaning, as shown in FIG. 5, by twisting the shroud to unlock it and pulling it off. The flange 132 of the shroud enables twisting. A door 102 to the reservoir 110 of the module may open to allow access to the propeller 126.

The illustrative housing of the axial pump further includes a flow straightener 132 and a deflector 134, though the invention is not so limited. The deflector automatically moves into position when coolant flows through the pump to serve as a velocity break for the coolant flow, ensuring that the pans fill evenly. The illustrative deflector 134 automatically moves down, as shown in FIG. 5, when there is no flow through the pump to allow for cleaning.

The flow distribution pan 140 receives the pumped coolant from the pump outlet 122 and distributes the coolant among the spray pans 150. The spray pans rain coolant over the passing product on the conveyor belt 20. The coolant then passes into the reservoir 110, where it is recirculated by the axial pump 120. The module continues to recirculate coolant over the product, reaching an equilibrium temperature.

The illustrative axial pump 120 has a relatively high flow rate, between about 150 and about 200 gallons per minute to create well-mixed coolant. In one embodiment, the flow rate is about twice the volume of the reservoir 110 to ensure well-mixed coolant in each zone.

The illustrative chilling system 10 allows coolant to flow naturally between temperature zones formed by modules in communication with each other. The outlet 122 of each pump returns coolant to the zone 110 from which the coolant was drawn to create an independent recirculation loop, while allowing some sharing of coolant between the zones via a communication means. For example, in an illustrative embodiment, the reservoir 110 of the first module 100 a includes a passage 170 for allowing overflow coolant from the first reservoir to pass into the reservoir of the adjacent downstream module 100 b. The passage is preferably below the conveyor belt 20. The coolant that spills into the downstream reservoir 110 b is generally warmer than the input coolant, due to heat exchange within the recirculating module of the coolant and the product on the conveyor belt 20.

The warmer coolant spills into the second reservoir via an input passage 171, and the second module 100 b recirculates the coolant using an axial pump, as described above, to create a temperature zone that is at a higher equilibrium temperature than the first module 100 a. The reservoir of the second module 100 b spills overflow coolant into the third module 100 c via an outlet passage or other communication means. The third module 100 c recirculates the coolant within a third zone around the conveyor belt 20 to create a third temperature zone having an equilibrium temperature that is higher than the second module equilibrium temperature. The third module spills coolant into a fourth module 100 d, which recirculates the coolant within a fourth zone at a higher equilibrium temperature. The outlet passage of the fourth module reservoir passes spent coolant into the outlet 15.

Preferably, each module 100 forms an independent recirculation zone, with a communication means, which can be a valve, passageway, opening, funnel or other suitable means, between the zones formed below the conveyor belt.

The flow of coolant over the product is independent of the input coolant, allowing a high level of coolant to spray over the product without increasing the amount of input coolant.

In one embodiment of the invention, the input coolant has a temperature of between about 30° and about 45° F. and the discharge coolant is between about 65° and about 80° F., though the invention is not so limited.

Although the invention has been described in detail with reference to a few exemplary versions, other versions are possible. The scope of the claims is not meant to be limited to the versions described in detail. 

What is claimed is:
 1. A chilling system for chilling products, comprising: a conveyor for conveying a product; and a plurality of recirculation modules, each recirculation module comprising a reservoir below the conveyor, a pump for pumping coolant from the reservoir, a pan for spraying pumped coolant over the product on the conveyor, and an outlet passageway in the reservoir for passing coolant into an adjacent reservoir or an outlet of the chilling system.
 2. The chilling system of claim 1, wherein the pan comprises an array of opening for creating a rainfall over the product.
 3. The chilling system of claim 1, wherein each recirculation module comprises a plurality of pans.
 4. The chilling system of claim 1, wherein the pump comprises an axial pump.
 5. The chilling system of claim 4, wherein the axial pump includes a removable flanged shroud.
 6. The chilling system of claim 4, wherein the axial pump includes an automatically engageable flow deflector.
 7. The chilling system of claim 1, wherein an inlet of the conveyor is at a first end of the chilling system and an inlet for coolant is at a second, opposite end of the chilling system.
 8. A recirculating module for a chiller, comprising: a reservoir having an inlet opening and a spillover opening; an inlet for a conveyor above the spillover opening; an outlet for the conveyor above the spillover opening; a pump having a pump inlet in communication with the reservoir, and a pump outlet; and a sprayer in communication with the pump outlet for spraying pumped coolant over items on the conveyor.
 9. The recirculating module of claim 8, wherein the pump is an axial pump.
 10. The recirculating module of claim 9, wherein the axial pump comprises a removable shroud.
 11. The chilling system of claim 9, wherein the axial pump includes an automatically engageable flow deflector.
 12. The recirculating module of claim 8, wherein the sprayer comprises a pan having an array of openings extending across the width of the conveyor.
 13. The recirculating module of claim 8, wherein the sprayer comprises a series of pans having arrays of openings.
 14. The recirculating module of claim 13, further comprising a flow distribution pan for dividing pumped coolant from the pump outlet into the series of pans.
 15. The recirculating module of claim 8, further comprising a conveyor belt extending through the inlet and the outlet for carrying product through the module.
 16. A method of changing the temperature of a product on a conveyor comprising: conveying a product through a chiller; spraying coolant over the product in a first zone using a first sprayer; collecting sprayed coolant in the first zone; pumping sprayed coolant in the first zone back to the first sprayer; passing overflow coolant from the first zone into a second zone; and spraying coolant over the product in the second zone using a second sprayer.
 17. The method of claim 16, further comprising the step of collecting sprayed coolant in the second zone.
 18. The method of claim 17, further comprising the step of pumping sprayed coolant in the second zone back to the second sprayer.
 19. The method of claim 18, further comprising the step of passing overflow coolant from the second zone into a third zone.
 20. The method of claim 16, wherein the first zone has a lower equilibrium temperature than the second zone. 